This invention relates to photographic materials. In the preferred form it relates to base materials for photographic display and portraits.
It is known in the art that photographic display materials are utilized for advertising, as well as decorative displays of photographic images. Since these display materials are used in advertising, the image quality of the display material is critical in expressing the quality message of the product or service being advertised. Further, a photographic display image needs to be high impact, as it attempts to draw consumer attention to the display material and the desired message being conveyed. Typical applications for display material include product and service advertising in public places such as airports, buses and sports stadiums, movie posters, and fine art photography. The desired attributes of a quality, high impact photographic display material are a slight blue density minimum, durability, sharpness, and flatness. Cost is also important, as display materials tend to be expensive compared with alternative display material technology, mainly lithographic images on paper. For display materials, traditional color paper is undesirable, as it suffers from a lack of durability for the handling, photoprocessing, and display of large format images.
Prior art photographic transmission display materials with incorporated diffusers have light sensitive silver halide emulsions coated directly onto a gelatin coated clear polyester sheet. Incorporated diffusers are necessary to diffuse the light source used to backlight transmission display materials. Without a diffuser, the light source would reduce the quality of the image. Typically, white pigments are coated in the bottommost layer of the imaging layers. Since light sensitive silver halide emulsions tend to be yellow because of the gelatin used as a binder for photographic emulsions, minimum density areas of a developed image will tend to appear yellow. A yellow white reduces the commercial value of a transmission display material because the imaging viewing public associates image quality with whiter whites. The transmission property of this imaged support is very good but typically the dye density is higher than a reflection display material in order to prevent the image from being washed out by the backlights. With the higher dye density, the image appears to be very dark and over-saturated, making it a non-usable material. Prior art photographic reflection display materials have light sensitive silver halide emulsions coated directly onto a gelatin coated pigmented polyester sheet. The reflective display material provides a somewhat pleasing image when viewed with reflective light but the transmission quality in not acceptable because of the high opacity of the base. It would be desirable if a transmission display material with an incorporated diffuser could have a more blue white, as this is perceived as preferred.
Prior art photographic display materials historically have been classified as either reflective or transmission. Reflective display materials typically are highly pigmented image supports with a light sensitive silver halide coating applied. Reflective display materials are typically used in commercial applications where an image is used to convey an idea or message. An application example of a reflective display material is product advertisement in a public area. Prior art reflective display materials have been optimized to provide a pleasing image using reflective light. Transmission display materials are used in commercial imaging applications and are typically backlit with a light source. Transmission display materials are typically a clear support with an incorporated diffuser coated with a light sensitive silver halide emulsion. Prior art transmission display materials have been optimized to provide a pleasing image when the image is backlit with a variety of light sources. Because prior art reflective and transmission products have been optimized to be either a reflection display image or a transmission display image, two separate product designs must exist in manufacturing and two inventories of display materials must be maintained at the commercial printer. Further, when the quality of the backlighting for transmission display material is reduced when, for example, a backlight burns out or the output of the backlight decreases with the age, the transmission image will appear dark and reduce the commercial value of the image. It would be desirable if an image support could function both as a reflection and transmission display material.
Prior art transmission display materials use a high coverage of light sensitive silver halide emulsion to increase the density of the image compared to photographic reflective print materials. While increasing the coverage does increase the density of the image in transmission space, the time to image development is also increased as the coverage increases. Typically, a high-density transmission display material has a developer time of 110 seconds compared to a developer time of 45 seconds or less for photographic print materials. Prior art high-density transmission display materials, when processed, reduce the productivity of the development lab. Further, coating a high coverage of emulsion requires additional drying of the emulsion in manufacturing reducing the productivity of emulsion coating machines. It would be desirable if a transmission display material was high in density and had a developer time less than 50 seconds.
Prior art photographic transmission display materials, while providing excellent image quality, tend to be expensive when compared with other quality imaging technologies such as ink jet imaging, thermal dye transfer imaging, and gravure printing. Since photographic transmission display materials require an additional imaging processing step compared to alternate quality imaging systems, the cost of a transmission photographic display can be higher than other quality imaging systems. The processing equipment investment required to process photographic transmission display materials also requires consumers to typically interface with a commercial processing lab increasing time to image. It would be desirable if a high quality transmission display support could utilize nonphotographic quality imaging technologies.
Photographic reflection/transmission display materials have considerable consumer appeal, as they allow images to be printed on high quality support for home or small business use. Consumer use of photographic display materials generally has been cost prohibitive since consumers typically do not have the required volume to justify the use of such materials. It would be desirable if a high quality reflection/transmission display material could be used in the home without a significant investment in equipment to print the image such as laser digital photographic printers.
There is a continuing need for an improved product that will present a bright reflective image when viewed directly and also provide a sharp bright image when backlit.
It is an object of the invention to overcome disadvantages of prior display materials.
It is another object to provide a superior, lower cost, and stronger display material.
It is a further object to provide a day/night display material that utilizes conventional optical photographic imaging technology.
It is another object to provide a day/night display material that utilizes nonphotographic imaging technology.
These and other objects of the invention are accomplished by an imaging element comprising in order an upper image, at least one transmission and reflection device providing optical transmission of between 35 to 55%, and a lower image, wherein at least the upper and lower images are on separate supports.
The invention provides a material that will when imaged will result in a bright sharp reflective image, as well as allowing for backlighting of the image to also result in a clear sharp image in low light situations. The invention further provides a simple means of forming a day/night image using any means of imparting indica on a media.